canon rumors FORUM

VerbalAlchemy

On the one hand, the 85 (or at least my copy) produces more CA than any lens I own. AF is snappy and accurate in good light-- but mine starts to hunt and miss focus as soon as twilight sets in, and I end up manually focusing half the time if I'm street shooting at night. Despite its maligned micro-USM autofocus, my 50 1.4 actually handles those kinds of situations more gracefully.

On the other hand, if I search in Aperture for my five-star rated photos, it turns out that the 85 is responsible for an inordinate number of them. So any operational frustrations are pretty much trumped by image quality-- especially for the price.

Given the crop body's tighter framing, I've found myself wishing for IS sometimes (not that the 135L has IS either for the FF equivalent)-- but I'm routinely able to get get workable shots with long shutters (managed to salvage a 1/10 handheld shot in the batch below), so it might not be a real concern. Plus, the IS-equipped lenses with comparable focal lengths have smaller apertures, reducing one of the 85's primary appeals: razor-thin DOF.

I took a long time deciding between this and the 100 f/2.0, ended up getting the 85/1.8 off ebay, they're listed nearly 10x as many compared to the 100 f/2, presumably if people want a good 100mm lens they give up one-stop of aperture to get one of the 1:1 f/2.8 macros (even though the 100/2 has a tiny bit better IQ than the 85/1.8 ).

Anyway, I don't want to say I just got this lens to take photos of a dog, but such a cute dog he is...7D, 85/1.8 @ f/2.8, iso200, 1/200s, 430EX with $5 chinese-ebay softbox (and a bit of PP taking out an unfortunately-positioned speaker against the wall in the background, cropped a bit)

I've had an 85 1.8 and a 100 f 2.0 for a while, but found them of limited use on my 5D classic due to the erratic autofocus system on that body. I recently got a 5D Mark III and it has transformed these lenses into useful portrait tools due to the much more accurate autofocus.

I'm still getting a feel for how these lenses work on the new body.

Here is a shot I took while walking around in Portland a few days ago with the 85 mm at 1/320, f 2.8, ISO 12,500. I cropped it about 15% in width and height. I brightened up the colors and contrast a bit with Lightroom, since it was shot under a bridge in very low light.

One negative thing about both the 85 and 100 USM lenses is the chromatic aberration. You can see it in this focus testing shot with the 85 wide open. The 100 is exactly the same. The squares are each one inch and I think I was about 8 feet away from the focus target which is the black horizontal band. You can see the purple fringing in front of the focus point.

The target is a cardboard 6 foot x 3 foot sewing layout mat that I place on the floor of my studio. I use the studio strobes to eliminate camera movement. I focus on the black band which is simply a piece of friction tape. If I'm doing Micro Focus Adjust, I'll use a tripod.

It is super-easy to find out where your lens has focused and if you take the time to line everything up precisely you can find problems like tilted lens elements that cause zones of blur.

I've had a lot of luck with this inexpensive system. I like it better than the popular focus testing units where the target is only a short distance from the lens. With this big target I can test at real life shooting distances.

Does the chromatic aberration affect my use of the 85 and 100 lenses? No, not at all. It goes away if you stop down one stop. Also, the zone where you get the purple fringing is in front of your subject. What is usually in front of your subject? Air. So there is nothing there to be aberrated, so to speak.